When troubleshooting telephone lines, it is desirable to monitor the signal on the line of interest without introducing noise or other spurious signals onto the line being monitored. Such monitoring has been performed in the past by placing a high impedance signal monitoring device across the line. This required gaining access to the line by, for example, electrically connecting some form of monitoring connector, such as a jack, across the line. The very act of inserting a monitor plug or similar connector into the jack, however, can diminish the accuracy of the monitoring process.